Commonly-owned U.S. Pat. No. 5,579,714 to Hemphill (the “Hemphill '714 Patent”) illustrates an exemplary divers' door for an inflatable or other boat. As disclosed in the Hemphill '714 Patent:                The diver's door includes a removable support section including a device for releasably attaching the support section to the deck of a boat and a corresponding removable tube element attached to the removable support section to form a single unit removable from the deck of a boat.See Hemphill '714 Patent, Abstract, 11. 4-9. To effect removal of the door from the boat for ingress or egress, the removable tube element is at least partially deflated to allow disengagement of the end cap of the removable element from a hoop flange. After the end cap is disengaged, the removable element may be grasped and removed from its position, thus creating an opening in the inflatable boat. See id., col. 4, 11. 34-38 and 46-53.        
Commonly-owned U.S. Pat. No. 5,832,864 to Hemphill (the “Hemphill '864 Patent”) details another divers' door for inflatable and similar boats. Like that of the Hemphill '714 Patent, the door of the Hemphill '864 Patent includes a removable inflatable element normally fitted between tubes of an inflatable boat. Likewise, removal of the element is effected by deflating it (at least partially). Both the Hemphill '714 Patent and the Hemphill '864 Patent are incorporated herein in their entireties by this reference.